[EM] Dumb question

[Stephane Rouillon]

Dear John,

approval and ranked pair are not as described proportional methods,
but you are right they could be used as inner motor to produce
proportional methods.
However, you have to be careful about how you do this.

The key into converting a single-winner method into a motor for
a proportional multiple-winner method is to make them able to produce
weights as an output. Why? Because of fairness issues: first a system
needs to be fair between parties, next between candidates and finally
between voters. It is one think to have a single-winner method that
avoids vote-splitting, does not favor cloning and gives an equal power
to every voters
(wheter approval fits or not is not the debate here), it is anoter
matter to preserve those
qualities while
building your proportional model using such a single-winner method.

For examples, take approval and let`s use it as you said to build a
proportional model. It is
obvious that it would introduce a bias toward parties with the same
program or alike.
Imagine all ridings with 3 parties at first, each with a 33% support.
Then one of the party
(Liberal for example) would split into three others over a detail,
presenting 3 candidates
for each riding. Instead of approving only my liberal candidate I would
approve all three
candidates. So the final support toward every party would now be
measured as 20% for
every party. Clearly the fractional support
becomes dependent of the number of candidates using such a method...

Works calls back, I will continue later.

Steph
PS: If you are interested SPPA on fairvote canada's site deals
with such issues...
http://www.fairvotecanada.org/phpBB/viewtopic.php?topic=8&forum=1&4

"John B. Hodges" a écrit :

  As a method of proportional representation, for electing members of a
  legislature, what would be the drawbacks of using Open Party List,
  with Approval voting (Or, for that matter, ranked-pairs Condorcet) to
  rank the candidates on each party's list? Candidate with greatest
  number of approvals goes to the head of the list, candidate with
  second-greatest number goes second, and so forth.

  One obvious tactic the nefarious party bosses could use would be to
  field only the number of candidates they expected the party could win
  seats for; this would nullify the effect of the open list. This
  tactic could be countered by legally requiring each party to put on
  the ballot everyone who had gathered X number of signatures from
  party members supporting their candidacy. Essentially this would
  require each party to hold a party primary, aspirants qualifying to
  be candidates by gathering signatures from some percent of party
  members. In the general election, anyone who votes for that party can
  either accept the ordered list that the party bosses provide, or fill
  out their approvals or rankings of the specific candidates on the
  list. The number of seats granted to the party would be proportional
  to the percent of voters who voted for that party, and who gets the
  seats would be determined by the approvals or rankings each candidate
  got.

  So, repeating the question: as a method of PR for legislative
  elections, what's wrong woth this picture?
  --
  ----------------------------------
  John B. Hodges, jbhodges@  @usit.net
  Do Justice, Love Mercy, and Be Irreverent.
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